Smoking weakens the immune system by depressing antibodies and cells that are in the body to protect against foreign invaders. There is an association between smoking and the increased incidence of certain malignant diseases and respiratory infections, according to the National Center for Biotechnology Information (NCBI). There is also a significant decrease in immune cells that normally help the body. But this process can be reversed if a smoker gives up cigarettes. Smokers who stop show increased levels of natural killer cell (NK) activity that targets cancerous cells in the body.

Many cancer-causing chemicals from cigarette smoke travel throughout a smoker’s bloodstream to reach the organs of the body and damage the immune response. Carbon monoxide is carried through the body by smoke, interfering with oxygen levels. Less oxygen reaches the brain, heart, muscles and other organs. Lung function is reduced because of the narrowing of the lung airways and excess mucus in the lungs.

Lung irritation and damage result from invading substances, leading to lung infection. Blood pressure and heart rate are affected negatively by smoking chemicals carried through the blood. The immune system does not work as well and smokers become more prone to infections, such as pneumonia and influenza. It takes smokers longer than nonsmokers to get over illnesses.

Smoking can cause the body’s immune system to attack lung tissue and result in severe respiratory disorders, according to research at the University of Cincinnati, Ohio. Health scientists examined mice to study the link between cigarette exposure, the immune system and chronic obstructive pulmonary disorder (COPD), a serious lung disease characterized by emphysema and severe inflammation of the lung tissue.

After lung cells were damaged from cigarette smoke in the lab research, the cells signaled the immune system when the damaged cells needed to be destroyed. The research shows that smoking actually activates certain parts of the immune system, which works against the lungs and attacks the tissue, it was reported in the March 2009 issue of the “Journal of Clinical Investigation.” The researchers found a strong correlation between cellular stress signals, activation of the immune system and development of diseases similar to COPD.

Researchers compared the results with tissue samples from humans who included nonsmokers, smokers with COPD and smokers who did not have COPD. They found that patients who had never smoked had no trace of the lung cells that triggered the immune system to attack lung tissue. Current and former smokers who developed the disease had evidence of those lung signals.

Several herbs are favored for their ability decrease immune system response. For instance, immunosuppressive herbs may work well for those taking medications for cancer, because the contrasting antioxidants could make cancer cells multiply faster. Many diuretics and laxative herb compounds are not only immunosuppressive but can also deplete stores of electrolytes like potassium, making the body more susceptible to heart attack or stroke. Consult with a medical doctor before attempting to self-medicate any condition.

Bupleurum-

Bupleurum, or Bupleurum falcatum, is an herb that has been used in traditional Chinese medicine for centuries as a treatment to bring the body back to a state of harmony. These practitioners believe that harmony resides in the liver, stomach and spleen. Bupleurum, according to Drugs.com, is being studied as an immunosuppressant herb in the role of certain cancers, gastrointestinal disorders and treatment of liver disease. Aside from its ability to suppress the immune system, bupleurum is also a known diuretic and laxative.

Glucosamine-

Glucosamine, or glucosamine sulfate, is a chemical present in the fluid surrounding joints in the body. Supplemental forms of glucosamine can come from natural sources such as shellfish or may be created in a laboratory. It is highly regarded and used today as a treatment for arthritis. In addition to possible immunosuppressive qualities, the University of Maryland Medical Center suggests that individuals taking nonsteroidal anti-inflammatory drugs with glucosamine exercise caution due to heightened risks of internal bleeding.

Red Yeast Rice-

Red yeast rice is a fermented yeast product traditionally used as a food coloring in Asian cuisine. It has been used for centuries in traditional Chinese medicine as an equivalent to today’s statin medications. Researchers have shown that in clinical laboratories, red yeast rice performed well in reducing bad cholesterol and may increase good cholesterol. Medline Plus, a National Institutes of Health website, further states that in addition to this herb working as an immunosuppressant, this herb may also harm the liver and should never be taken with alcohol or in combination with other statin drugs.

Cascara Sagrada-

Cascara sagrada, or yellow bark, is a natural stimulant laxative used to relieve constipation. Like other diuretic and laxative herbs, Brigham and Women’s Hospital suggests that the immune system can become compromised when they are used for extended periods and could lead to cancer. This herb is generally considered safe for short-term use, yet it can increase opportunity for infection, dehydration, low electrolytes and heart problems and can cause muscle weakness if used for more than a few days. Individuals with pre-existing gastrointestinal disorders are strongly cautioned against using cascara sagrada.

Your immune system is a complex network responsible for fighting off harmful bacterial, viruses and chemicals. It also operates as an alarm system of sorts for developing cancers, reports the Cleveland Clinic. Celiac disease is an autoimmune condition that results in an inappropriate stimulation of the immune system when gluten is consumed. If you have gluten intolerance you may experience many symptoms of celiac disease without the severe intestinal damage. Gluten does not prompt this response in individuals who do not have celiac disease or gluten intolerance.

Gluten-

Gluten is a protein found in certain grains, including barley, rye and wheat. Gluten is found in crossbreeds of these grains, as well as in any packaged or processed foods containing these grains. Gluten is challenging to avoid as wheat, barley, rye or derivatives of these grains are common additives in food processing. These grains might also be present in medications, lip balms and other skin products.

Gluten Intolerance-

With celiac disease and gluten intolerance, your small intestine is primarily affected; ingesting gluten prompts an immune response. Your immune system is inappropriately activated, which impairs your body’s ability to absorb nutrients. You might experience symptoms such as bloating, diarrhea, gas, skin lesions and constipation. Over time, if a gluten-free diet is not followed, you may develop malnourishment and vitamin deficiencies.

Gluten and Immune System-

Celiac disease activates your immune system rather than suppressing it; however, it might lower your immune system due to malnutrition. According to the Cleveland Clinic, even marginal deficiencies in nutrients might contribute to a lowered immune system. A daily multivitamin might be useful in preventing malnutrition; however, you may require blood testing to identify nutrient deficiencies such as iron. An autoimmune response places stress on the immune system, which might leave you more susceptible to illness.

Gluten-Free Dangers-

Gluten-free diets are unnecessary and potentially harmful for those who do not have celiac disease. Eating gluten-free foods unnecessarily might lead to weight gain if you are substituting gluten-free replacement products, as these products are often higher in sugar and fats than their counterparts. Gluten-free diets often lack sufficient nutrients, reports the September 2006 issue of “Practical Gastroenterology.” These nutrients may include calcium, fiber, iron, thiamin, folatem, riboflavin and niacin. Removing gluten unnecessarily might also contribute to vitamin deficiencies that lower your immune system.

Nutrition impacts the strength of your immune system and ability to fight infections and protect your health. Dairy is a big part of the human diet, providing a rich source of protein, calcium and other nutrients. Eating fermented dairy may help you build a strong immune system. However, if you have allergies, dairy can impair your immune system. Consult your doctor about the effects dairy has on your immune system.

Dairy-

Dairy is a broad category of foods that are derived from cow’s milk. These foods include whole milk, skim milk, low-fat milk, butter, cheese, cottage cheese, sour cream, ice cream and yogurt. Dairy products also include milk proteins, such as casein and whey, that manufacturers use in processed foods. Contrary to what many people may believe, eggs are not considered dairy products, particularly because they come from chickens and not cows.

Immune System-

Your immune system protects you from foreign substance and microorganisms, including bacteria, viruses, parasites and fungi. The digestive tract is a common entry point for many foreign substances and pathological organisms. Foreign substances, such as certain proteins, are called antigens that activate your white blood cells to attack and annihilate the antigen. In response to antigens, your body releases antibodies, lymphocytes, phagocytes and other types of immune cells to protect your body from damage these foreign substances and organisms may cause.

Dairy Allergies-

An allergy to milk or other dairy products are among the most common food allergies. These allergies cause numerous health problems. An allergy is defined as an immune response to a substance that causes inflammation and tissue damage in any part of your body. However, the substances in most allergies, including milk and dairy, are usually harmless and it is the body’s reaction that causes the most problems. A milk and dairy allergy causes ear infections in children, inflammation of the sinus, heartburn, diarrhea, irritable bowel syndrome, constipation, anxiety and irritability. Symptoms from a milk and dairy allergy may not show up until hours or days after you have eaten these foods. Lactose intolerance, however, is not an allergy to milk and dairy even though symptoms may be similar. Lactose intolerance is defined as a deficiency in lactase, the enzyme that digests lactose, a sugar in milk.

Fermented Dairy Products-

Eating fermented dairy products enhances your immune system and protects you from gastrointestinal and respiratory infections. Scientists at Danone Research in Palaiseau Cedex, France found that consumption of fermented dairy products containing Lactobacillus casei DN-114 001 may reduce the risk of common gastrointestinal and respiratory infections in shift workers, according to research published in the “Journal of the American College of Nutrition” in October 2010. The scientists report that the risks of infections among shift workers are normally higher than the general population. The results demonstrate that fermented dairy enhances your immune system, even when you are experiencing stress.

Probiotics are beneficial bacteria that live in our bodies and can also be found naturally in certain foods and beverages. These living micro-organisms support normal health and help to enhance and repopulate intestinal bacteria, balancing gut flora and boosting immunity. Probiotics are beneficial to overall health and gastrointestinal health especially. “Pro” and “biota” literally translates to “for life.”

Functions of Probiotics-

The weight of all of the bacteria within our intestines is more than three pounds, totaling more than 100 trillion bacteria, which belong to more than 500 different species that reside in every healthy bowel. The majority of these are not the type of bacteria that make us ill; rather, most are helpful and keep harmful pathogens at bay. They aid digestion, immune function and nutrient absorption. They are responsible for synthesizing nutrients in the intestinal tract such as folic acid, niacin, riboflavin, vitamins B6 and B12. If these beneficial bacteria become depleted due to poor diet, disease, stress, or the over-use of medications such as antibiotics, health problems can result. Under healthy conditions, the good bacteria will thrive.

Treatment of Health Conditions-

Probiotics have been used for centuries by many cultures, in the treatment of various health conditions. They are used in treatment for lactose intolerance, diarrhea, constipation, Crohn’s disease, ulcerative colitis, Irritable Bowel Syndrome, yeast overgrowth and infections, urinary tract infections and rheumatoid arthritis. Probiotics have been successful in lowering cholesterol and inflammation, reducing the risk and severity of allergic disease including eczema, and may assist in preventing cancers, particularly bladder and intestinal cancers. Side effects are uncommon, and most adults and even children can safely add foods that contain probiotics to their diet.

Probiotic Supplementation-

Probiotic supplements may be used when dietary intake is unable to meet the needs for bacterial normalization. The Harvard Medical School recommends doses that range from 1 to 10 billion colony-forming units, which is the equivalent of one or two capsules, taken several days per week. Different effects may be observed, depending on the amount and the species and the strain of the microorganism used. All strains are not considered equally useful, so consider consulting a practitioner who is familiar with probiotics to determine which are best for you. For overall good health, supplementation is not necessary, as good bacteria obtained from certain foods will do the trick.

Digestive Health-

Friendly probiotic bacteria help reduce inflammation in the intestinal tract and colonize it with healthy bacteria, allowing it to function properly. They repair damaged intestinal walls so that healing may occur. Digestive conditions improved with probiotic treatment include Crohn’s disease, ulcerative colitis, IBS, lactose intolerance, constipation, and diarrhea. The probiotics lactobacilli and bifidobacteria are especially helpful in treating diarrhea in infants, children and adults. A daily supplement for one to two weeks may improve infectious or antibiotic-related diarrhea. Effects vary, depending on the person and on the nature of the condition.

Immune Strengthening Powers-

About 80 percent of our immune system function takes place in the intestinal tract; therefore, digestive health is directly related to immunity and overall health. The probiotic bacteria in the intestinal tract activate immune system components such as T and B lymphocytes, which are immune cells important for fighting against and preventing infection. Probiotics may help protect against certain cancers and may also prevent or reduce the severity of colds and flu. They can help strengthen an immune system that has been weakened.

Probiotic Foods-

It is best to obtain probiotics from foods first, before turning to supplements, according to Kristi King, of the Academy of Nutrition and Dietetics. When obtained from foods, probiotics “are more readily available for absorption and digestion,” she says. Probiotics can be found in live-cultured yogurt, kefir, miso, sauerkraut, kimchi, kombucha, aged cheeses, olives, algae plants such as spirulina, chlorella, blue-green algae, and pickled vegetables. Some of the most common types of probiotic bacteria are lactobacillus acidophilus and bulgaricus, and streptococcus thermophilus.

Vitamin C plays a part in the health maintenance of many tissues, and it is an integral component for the production of collagen, a protein involved in the healing of wounds, blood vessels and the skin. Along with its role in skin health and beauty, many scientific studies suggest that vitamin C can boost your immune system, but it is not a definitive fact.

How Much Vitamin C-

Also known as ascorbic acid, vitamin C is water-soluble. This means that the body does not store it, so you need a daily supply of this vitamin to avoid deficiencies. The ideal daily dose of vitamin C ranges from 40 micrograms in babies to between 75 and 90 micrograms for adults. Breast-feeding mothers and smokers need a higher daily dose.

Sources of Vitamin C-

Fruits and vegetables are natural sources of ascorbic acid. In particular, citrus fruits like lemons, oranges and grapefruits; berries, like blueberries and strawberries; and tomatoes are good sources of vitamin C. Other natural sources of vitamin C include potatoes, green peppers, broccoli, turnip greens and other leafy vegetables. Fortified breakfast cereals and dairy products are also good sources of vitamin C.

Immune System Effects-

The effect of vitamin C on the immune system remains controversial. Vitamin C has been proposed as a cure and prevention for the common cold and other respiratory infections. Although vitamin C may play a role in the prevention of pneumonia, for example, more studies are needed to confirm this benefit. Research on the positive effects of vitamin C on diabetes, asthma and heart disease has not been conclusive. Many studies looking into vitamin C’s effect on the immune system have not conclusively answered the question of its effectiveness.

Vitamin C Deficiency-

If you don’t get enough vitamin C, you can develop signs of scurvy. This condition causes inflammation and bleeding of the gums, weakness, easy bruising and poor wound healing. Other symptoms include joint pain, anemia and loose teeth. The treatment of scurvy includes increasing the consumption of vitamin C-rich foods or taking oral supplements. The symptoms of scurvy usually disappear within a week or two of taking adequate doses of vitamin C. Never add supplements to your daily routine without consulting a physician first.

The immune system is defined by the National Cancer Institute as a complex system of cells, organs and tissues that protect the body from bacteria, viruses and micro-organisms that try to invade it. Scientists and researchers have known for years that there is a connection between stress and the immune system. Stress suppresses immune system function and that, over time, the immune system does not adapt but instead continues to wear away. What was intended to protect the body and begins to harm it when unregulated. The effect of stress on the immune system has been linked to cancer, AIDS and other autoimmune disorders.

Too Much Stress

The way stress affects the immune system is complicated but in essence stress produces a hormone in the body called cortisol. The brain recognizes cortisol as the “fight or flight” hormone, and when it is produced, other body functions are halted until the stressful situation has passed. This is the body’s way of taking care of an immediate emergency. The immune system also receives signals to slow down while cortisol does its job. But with chronic stress, however, the immune system stays in low gear, leaving the body vulnerable to infection and disease. Common illnesses brought on or worsened by stress are cardiovascular disease, digestive problems, skin conditions and poor memory function.

Too Little Stress

Too little stress in the body as well. If that happens, there is no system that puts the immune system in check. When left to do what it wants, the immune system often begins attacking healthy invaders, and when that happens, you can develop inflammatory diseases like arthritis or tendinitis. The general population, however, does not have to worry about too little stress.

Controlling Stress for Immune Function

The Mayo Clinic reports that when the levels of stress hormones drop, then other body processes such as heart rate and immune function return to normal. As cortisol levels drop, the immune system cells begin to resume their role of protecting the body.

While you cannot avoid all of the stresses that come your way, you can learn how to control your reaction. Learning to deal with stress in a healthy manner will minimize the negative affects it has on the immune system. The Mayo Clinic recommends meditation, exercise, counseling and good interpersonal relationships as constructive ways to handle life’s daily challenges.

Your digestive tract has an important relationship with your immune system, since the digestive tract is one of the mechanisms through which you’re exposed to tremendous numbers of pathogenic organisms each day. The immune system works with the digestive tract to help protect you from infection by these potential invaders.

Digestive Tract-

Your digestive tract extends from your mouth to your anus, and includes the stomach, small intestine, and large intestine. It’s the system responsible for breaking down large molecules in your food into smaller molecules that you can absorb, and it’s essentially an exterior surface of the body, since it’s regularly exposed to outside substances. Because of this, it’s exposed to bacteria and viruses on a regular basis, and its absorbent lining and moist, dark atmosphere would be ideal for pathogenic colonization if it weren’t for the immune system.

Immune System-

Your immune system consists of a complex network of organs, as well as cells and proteins. Antibodies, for instance — though they’re probably the best-known aspect of the immune system as far as the general public is concerned — are just one small component of the system. Your immune system also depends upon cells to kill invading organisms, and chemicals that don’t require the involvement of cells at all, but which are simply toxic to bacteria and viruses.

Innate Immunity-

Innate immune responses are non-specific, and don’t require exposure to a pathogen to trigger them. Your digestive system depends upon many innate immune responses, such as the lysozyme you secrete in saliva, which breaks down bacterial cells. Acid in the stomach does the same thing. In this way, the digestive tract actually helps the immune system to protect the rest of the body by preventing exposure to pathogens.

Acquired Immunity-

Acquired immunity requires that you’ve been exposed to a pathogen; once you’ve been exposed, your cells recognize that pathogen as an invader and can fight it off. Antibodies are a major component of acquired immune responses; you build antibodies to the pathogens to which you’ve been exposed. Some of these — called IgA — you express on the mucous surface of the gut. These help kill pathogens before they can colonize the intestine.

Your immune system is a network that works to keep harmful substances, such as viruses, bacteria and chemicals, from entering and triggering disease in the body. While a strong immune system lowers your risk for health problems and enhances healing once you have them, poor immune function increases your risk for illness and can slow or prevent healing. A healthy diet, limited in certain foods, may guard against these risks.

Red Meat –

Red meat is a top source of saturated fat, which may increase inflammation in your body — a common way your body reacts to harmful substances, injuries and disease. For boosted immune function switch red meat out of your diet in exchange for another source of protein. Choose oily fish for protein instead. Oily fish, such as salmon, mackerel and halibut, provide omega-3 fatty acids — essential fats with anti-inflammatory properties.

Fried Foods –

Fried foods, such as potato chips, french fries and fried pastries, are additional rich sources of saturated fat. Many also contain trans-fats, which can increase your LDL, or “bad” cholesterol and reduce your HDL, or “good” cholesterol, according to the American Heart Association, increasing your risk for heart disease significantly. For heightened benefits, replace fried foods in your diet with moderate amounts of healthy fat sources, such as nuts, seeds, avocados and vegetable oils.

Added Sugars –

Added sugars contribute sweet flavor and calories, but few nutrients, to foods. Consuming 8 tablespoons of sugar, or the amount found in one 12-ounce can of soda, can reduce your white blood cells’ ability to destroy germs by 40 percent, according to the Environmental Law Center of the United Kingdom. This immune-suppressing effect may begin within 30 minutes of ingestion and last for up to 5 hours. Other particularly sugar-rich foods include candy, colorful cereals, pancake syrup, jelly, jam, frosting, frozen desserts and commercially-prepared cakes, cookies, pastries and pies. Healthier alternatives include unsweetened apple sauce, all-fruit frozen bars, tea sweetened with stevia and low-sugar bran muffins.

Refined Grains –

Refined grains, such as white flour, instant rice and enriched pasta, contain few nutrients and little fiber compared to the natural whole grains they derive from. Increasing your fiber intake strengthens your immune function, so swap white bread and other refined foods out for 100 percent whole grain alternatives. Nutritious options include oats, barley, wild rice, brown rice and air-popped popcorn.

Green tea is a beverage that has been consumed in Eastern cultures since ancient times for its perceived effects on health. Now consumed globally as a favored beverage, green tea is of greater scientific interest, due to its potentially positive effects on the mind and body, particularly on the immune system. By strengthening immune agents, protecting against oxidative stress that can damage cells and preventing autoimmune disorders like rheumatoid arthritis, green tea is thought to be highly beneficial for the human body.

Prevention of Cancer Through Antioxidant Activity –

Catechin, a type of antioxidant in green tea, is thought to have a role in protecting against certain types of cancer, including mammary cancer after its initial growth has begun. These catechins are thought to function as tumor-fighting agents, directly preventing the growth of cancerous tumors, but they are also important in supporting the immune system as a response to exposure to carcinogens, or known cancer-causing compounds.

Strengthening Effects on Other Immune Agents –

Aside from their anti-cancerous properties, the antioxidants in green tea are beneficial in generally strengthening the immune system. By protecting it against damage from compounds known as free radicals and similar compounds in the body, green tea keeps the immune system running normally. Healthy immune systems are better at handling infections from bacteria, parasites and viruses.

Management of Autoimmune Disease –

Certain antioxidants called polyphenols in green tea have anti-inflammatory properties, resulting in a fundamental change in immune system response that could be beneficial in managing rheumatoid arthritis and other autoimmune diseases. Rats suffering from autoimmune arthritis that were fed green tea had higher levels of the immune system-boosting compound cytokine IL-10 compared to the control group, and demonstrated significantly reduced symptom severity. Green tea-fed rats also had lower levels of inflammatory cytokine interleukin (IL)-17, which is thought to have contributed to the reduced autoimmune inflammatory response.

Protection Against Ultraviolet Damage –

In a function related to its anti-cancerous properties, green tea also protects the body against damage from ultraviolet light rays. Drinking green tea prevented inflammatory and immune system-suppressing responses ordinarily associated with ultraviolet exposure. This function protects the immune system against UV damage and reduces the severity of several skin problems associated with that damage. The same study suggested that topical use of epigallocatechin-3-gallate, a compound found in green tea, held a similar protective function.